We show that two boundaries of the Somalia tectonic plate (western and southern), which are not defined well by traced epicenters of earthquakes, become defined well when we present the spatial distribution of these epicenters not in geographic coordinate system, but as a plot of distribution of the geomagnetic Inclination in the epicenters versus a longitude. This supports a suggestion that the intra-terrestrials processes, one of which is responsible for plate tectonics, and another for generating the main geomagnetic field, are coupled. We suggest that the lack of an intersection between the western boundary of the Somalia plate and the Southwest Indian Ridge, as it is expected, is somehow related to the existence of the South Atlantic Magnetic Anomaly.